The current invention relates to the field of multi-media computers and specifically to the process of synchronizing music with a visual display.
It is desirable for many types of computer programs to have audio output, either in the form of tones, words or music, in addition to video output, in the form of text or images displayed on a computer monitor screen. Many computer programs have moving images which appear on the screen as video output. In many circumstances it would be desirable to have audio output timed or synchronized with the visual output.
With a computer it is currently possible to store files containing audio-visual data, such as moving images, on computer readable storage media and display the data on a computer screen. This is often done with the use of compact disc (CD) storage devices, such as CD-ROM or CD-WORM. CD's are often used because of the large volume of storage which they can support.
In many instances CD storage devices can also be used on computer as conventional music CD players. These devices allow conventional audio CD's to played, for audio output, on a computer equipped with amplified stereo speakers or if connected to a stereo system.
One of the problems encountered in the use of CD computer storage devices to play audio CD's is that they all run at different speeds and these speeds cannot be easily controlled by a computer.
This has created a problem for computer programmers who wanted to display video images on the computer and time this with an audio CD track on the attached CD. While they could easily queue the audio track to begin at a designated time, i.e. at the beginning of a series of visual images, once the audio track started it could not be controlled to assure that the audio track would stay in time with the visual images. This is especially true since each CD player runs at a slightly different speed. Therefore, although an audio track may be synchronized to a visual display on a certain computer system, if the same program were to be run on a different computer system the timing would not be the same and the synchronization would not work.
One specific type of computer program where this problem is common is in Karaoke programs. In Karaoke, a popular song is played without the lyrics, and people sing along to the music. Often, the lyrics are either written down on paper for the people so they can sing along to the song. In other versions, the lyrics may be displayed for the persons singing. In some versions of Karaoke, the lyrics are shown to the person singing with the specific words highlighted or emphasized in some manner at the time they are to be sung. This is to help the singer synchronize the words to the music.
In most Karaoke systems, the display highlights the words to be sung by sweeping a highlight color or bar continuously across the words shown or emphasizes the word to be sung at a particular point in the music. This often leads to missed timing because, often in songs it is not merely the words that need to be timed to the music, but rather the individual syllables.